Abstract

Raman spectroscopy is often used for material identification but may be used for characterization. This document focuses on using Raman measurements to characterize polymers, specifically the curing and aging mechanism for hydroxyl-terminated polybutadiene (HTPB). HTPB is a well-known elastomer used in sealants, non-slip surfaces, rocket repellants and plastic explosives. Raman spectroscopy was used to monitor urethane linkages that form from curing HTPB with a cyanate curing agent to suggest a curing mechanism for HTPB. Since this polymer is highly susceptible to oxidation, the methods used to characterize curing were also used for the aging process to see if urethane breakages could be observed. Raman measurements were compared to elongation-at-break measurements to assess the short-term aging process. Results showed that oxidation of the urethane linkage seemed to be the primary source of degradation during early thermal aging. Patterns seen in Raman data may be studied to suggest an oxidation mechanism at the urethane site as a starting point to unravel the network of aging mechanisms for HTPB. Additionally, a recently published mount design is discussed for sustained tensile strain. The mount setup was used to mechanically extend samples while taking real-time spectroscopic data. Testing for the mount was done on HTPB and high-density polyethylene, but the design may accommodate a large variety of materials and is compatible with many spectroscopic methods including Raman spectroscopy.

Degree

PhD

College and Department

Computational, Mathematical, and Physical Sciences; Chemistry and Biochemistry

Rights

https://lib.byu.edu/about/copyright/